New therapies and improved diagnoses of bladder cancer have significantly lowered the number of deaths from the disease. However, bladder cancer remains a significant cause of morbidity and mortality in the United States and many other countries.
Smoking is a significant risk factor for bladder cancer because many of the cancer-causing chemicals in tobacco smoke are absorbed by the lungs, filtered by the kidneys, and excreted into the urine. When the urine is stored in the bladder, these chemicals can then damage the cells lining the bladder. The most common symptom of bladder cancer is blood in the urine.
There are three main types of bladder cancer:                i) Urothelian Carcinoma. Also called transitional cell carcinoma, this is the most common type of bladder cancer, occurring in 90 percent of all cases.        
These cancers are usually superficial (75 percent of the time) and haven't gone very far into the bladder;                ii) Squamous Cell Carcinoma. Accounts for three to eight percent of bladder cancers, and is likely to have invaded farther into the bladder than urothelian carcinoma; and        iii) Adenocarcinoma. Also likely to involve deeper layers of the bladder; accounts for a small fraction of bladder cancers.        
In cases of bladder cancer, cancer cells invade the wall of the bladder. The wall of the bladder consists of several layers and the treatment modalities used to treat bladder cancer are typically selected on the basis of how far the cancer has penetrated into the layers of the bladder wall.
The majority of superficial tumors (e.g., those that are confined to the mucosa and lamina propria of the bladder) are treated by urologists by way of cystoscopic surgery and in select cases intravesical drug therapy. Although these superficial bladder cancers frequently recur and may be multifocal, the survival rates following treatment are generally excellent. However, in cases where the carcinoma has penetrated the muscular wall of the bladder (i.e. where the cancer has progressed to invasive bladder cancer that invades the deeper layers of the bladder wall, and possibly nearby organs, such as the uterus, vagina, or prostate gland) the prognosis is typically worse. Approximately 50% of patients with muscle-invasive bladder cancer will develop metastatic disease. For this reason, there is a clear need for effective systemic therapy for bladder cancer.
A variety of single agents have significant activity in transitional cell carcinoma of the bladder. Cisplatin-based regimens such as MVAC (methotrexate, vinblastine, doxorubicin, and cisplatin) have become standard for patients with metastatic urothelial carcinoma. The response rate to this combination therapy developed almost 20 years ago has been found to be as high as 72% with a 36% complete response rate (Stemberg, C. N. et al; Cancer 1989, 64, 2448). The median survival of patients with metastatic bladder cancer treated with M-VAC is approximately 1 year and long-term survival occurs in a small proportion of patients. Randomized trials have demonstrated that MVAC is superior to single-agent cisplatin and to CISCA (cyclophosphamide, doxorubicin, and cisplatin) (Loehrer, P. J. et.al., J. Clin. Oncol. 1992, 10, 1066 and Logothetis, C. J. et.al., J. Clin. Oncol. 1990, 8, 1050). However, the drawback of MVAC is toxicity and poor patient tolerance. In clinical trials, the combination had substantially more toxicity including mucositis, myelosuppression, and treatment-related deaths than did single-agent cisplatin. Additionally, patients with advanced urothelial carcinoma may have age- and/or disease-related abnormalities in renal function making the utilization of a cisplatin-based regimen problematic. Nonetheless, MVAC remains an important landmark in the development of chemotherapy in bladder cancer.
Further attempts to improve results with MVAC have focused on circumventing toxicity and intensifying dose. The utilization of the hematopoietic growth factor granulocyte-colony stimulating factor (G-CSF) has shown reduction in some of the toxicities, including decreased number of days of significant granulocytopenia, the need for antibiotics for granulocytopenic fever, and the incidence and severity of mucositis, associated with the MVAC regimen. However, dose intensification of MVAC utilizing hematopoietic growth factors has been attempted in several studies, with generally disappointing results (Seidman, A. D. et.al., J. Clin. Oncol. 1993, 11, 408 and Logothetis, C. J. et.al., J. Clin. Oncol. 1995,13, 2272).
Thus, MVAC is an active but toxic regimen for advanced bladder cancer. Given the small chance for long-term survival for most patients treated with this regimen, efforts to identify new agents and combinations with improved efficacy or tolerability have been ongoing.
New agents with significant activity include the taxanes paclitaxel and docetaxel, gemcitabine, ifosfamide, and the methotrexate analogues, trimetrexate and piritrexim. A large number of phase I-II trials have evaluated these agents in two- and three-drug combination regimens Paclitaxel demonstrated significant activity against human bladder cancer cell lines and in Phase II trial, paclitaxel with prophylactic G-CSF in patients with previously untreated advanced transitional cell carcinoma of the urothelium demonstrated an objective response (response rate of 42%). Toxicities included granulocytopenia, anemia, mucositis, and neuropathy. This study demonstrated that paclitaxel is among the most active single agents in this disease site (Roth, B. J. et. al., J. Clin. Oncol. 1994, 12, 2264). Based on this initial trial, paclitaxel-based regimens have been developed including doublet and triplet combinations with carboplatin, cisplatin, gemcitabine, ifosfamide, methotrexate, and other agents.
Gemcitabine is a deoxycitidine antimetabolite with a structure similar to cytarabine and has been approved for the palliative treatment of patients with advanced pancreas cancer. Gemcitabine has broad antitumor activity, including in bladder cancer. Response rates in the clinical trials were less than 30% and median survival was less than 12 months. In all these phase II trials, toxicity was in general mild and reversible. Combination of gemcitabine and cisplatin showed a better response rate (41%) but toxicity included grade 3-4 granulocytopenia and thrombocytopenia.
A better understanding of the molecular biology of bladder cancer will undoubtedly influence the selection of new therapeutic modalities. Molecular targeted small molecule therapy and monoclonal antibodies have begun to dominate contemporary studies. Whether or not this approach to therapy will lead to better results must still be determined in clinical trials.
Although only 20% of bladder cancers are clinically advanced at presentation, up to one-half of patients with infiltrating disease will recur or develop metastases and will die. On the basis of the relatively high response rate obtained with combination chemotherapy in patients with advanced or metastatic transitional cell carcinoma, urothelial cancer can be considered a chemosensitive disease. Nevertheless, long-term survival remains low and chemotherapy may provide the potential for cure only in selected patients.
Although several active combinations incorporating new agents, such as Gemcitabine and paclitaxel, have been evaluated in recent years, there are, at the moment, no clear-cut data demonstrating that these regimens are able to improve patient survival or to prolong response duration.
Chalcones and flavones are abundantly present in nature from ferns to higher plants. Chalcones are aromatic compounds and exhibit the basic structure with two benzene rings linked through an α,β-unsaturated carbonyl group (Formula 1). The flavones are phenylbenzo-pyrones (phenylchromones) with an assortment of structures based on a common three-ring nucleus. The basic flavone structure is comprised of two benzene rings (A and B) linked through a heterocyclic pyrone ring in the middle (Formula 2).
Chalcones have been reported to be anti-inflammatory, analgesic and antipyretic, whereas flavones show many pharmacological properties. Some chalcones possess bactericidal, antifungal and insecticidal activity and some of their derivatives are reported to be antimutagenic. Piper methysticum Forst. f. (Kava Kava) belongs to the family Piperaceae, and grows as a perennial shrub in Fiji and other South Pacific islands, where its root extract has been traditionally used as a beverage for thousands of years in social, recreational and ceremonial events, and also as a remedy for stress and anxiety. Due to its beneficial health effects, P. methysticum has gained popularity recently in western countries as an alternative medicine especially for the treatment of anxiety disorders. The chemistry of P. methysticum has been extensively studied, and SO far more than 40 compounds belonging to the classes of kavapyrones, alkaloids, steroids, chalcones, long-chained fatty acids and alcohols have been isolated and identified. Among these compounds, kavalactones have been recognized as the constituents responsible for the reported biological activities in Kava. Eighteen different kavalactones have been reported from the root extracts of Kava and desmethoxyyangonin, yangonin, dihydrokawain, kawain, dihydromethysticin and methysticin are the most abundant. Three chalcones, Flavokawains A, B and C were also isolated and synthesis of these have been previously reported (Dutta et. al., 1978. J. Indian Chem. Soc., 55, 932 and references cited therein; He et. al. 1997. Planta Medica, 63, 70; Ranjith et. al. 2002. Phytochemistry, 59, 429. Also see, Ono et. al. U.S. Pat. No. 6,303,157, issued Oct. 16, 2001 and McCleary et. al. PCT Int. Appl. 2002 WO 0291966). Wu et. al. (J. Agric. Food Chem. 2002, 50, 701) have shown that root extract demonstrates good to moderate inhibition against cyclooxygenase (COX) enzymes. The extract from above-ground growing parts of Piper methysticum Forst, especially leaves, shows a different chemical and pharmacological profile (Bueter, PCT Int. Appl. 2002 WO 0207743).
However, there are only scanty reports on the activity of chalcones against cancer. Anto et.al. (Cancer Letters 1995, 97, 33) investigated synthetic chalcones for their cytotoxic and tumor reducing activities. Methyl and hydroxy substituted chalcones were found to be cytotoxic in vitro whereas only hydroxy substituted chalcones could reduce ascites tumor in animals. However, anticancer activity of chalcone derivatives of this invention has not been reported. On the other hand, a study by Reina et. al. (Nutrition and Cancer 1999, 35, 212) did not find any relationship of bladder cancer occurrence and dietary intake of carotenoids (α-carotene, β-carotene, lutein and lycopene) and flavonoids (quercetin, kaempferol, myricetin and luteolin) and concluded that the study did not support the hypothesis that these specific carotenoids and flavonoids are protective against bladder cancer. It is most likely that the amount of flavones derivatives of this invention were not adequate to exert a pharmacological effect.